Vulnerable small

Materials routinely copied or backed up to an independently managed, off-site data storage facility and able to be restored under contractual terms.

Group: Storage

Trend in 2021:

Consensus Decision

Added to List: 2019

increased risk Trend towards greater risk

Previous classification: Vulnerable


Trend in 2022:


No change No Change


Imminence of Action

Action is recommended within three years, detailed assessment within one year.

Significance of Loss

The loss of tools, data or services within this group would impact on many people and sectors.

Effort to Preserve

It would require a small effort to preserve materials in this group, requiring the application of proven tools and techniques.


Remote network storage provided by a third-party service under contract, such as DropBox, Amazon, Microsoft Azure, Dell EMC, Google Cloud Platform, Google Drive, IBM, Intel, Rackspace, Iron Mountain, SAP, and others

‘Endangered’ in the Presence of Aggravating Conditions

Encryption; lack of routine maintenance; lack of storage replication; over-dependence on single supplier; insufficient documentation; lack of local alternative; political or commercial instability; overly aggressive compression; poor information security; lack of transparent integrity-checking; lack of strategic investment; lack of migration plan; lack of exit strategy; unenforceable penalties; unstable pricing; unpredictable removal costs

‘Lower Risk’ in the Presence of Good Practice

Backup to different technology; backup to diverse locations; documentation of assets; integrity checking; preservation planning; export functionality; resilient to hacking; version control; resilient funding; technology watch; enforceable contract; disaster planning and documentation, stable pricing; budgeted removal costs.

2021 Jury Review

This entry was added in 2019 to ensure that the range of media storage is properly assessed and presented. The 2021 Jury noted increased risk in light of greater reliance on the cloud and localized disruptions to cloud services over the pandemic. The 2021 trend towards greater risk is based on the wider (global) dependence on these services, especially Google Drive, for record keeping and business workflows. The impact of loss increases with much more reliance on cloud services leading to greater risk; however, this should not deter people from using cloud storage. Therefore, the vulnerable classification stands so long there are safeguards in place.

Additional Comments

The history of digital preservation suggests that the risk of vendors going out of business or shutting down services is the key issue here, over and above any specific technical solutions or risks.

Case Studies or Examples:

See also: Digital Preservation Coalition (2016) ‘Storage’ in Digital Preservation Handbook (Second Edition), online at

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